Free Current Electricity MCQs with Answers
1,052 Current Electricity MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
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1,052 questions · page 39 of 53
- A. Rate of flow of charge
- B. Rate of flow of momentum
- C. Rate of flow of power
- D. None of them
Explanation: Electric current may be defined as the rate of flow of charge. Electric current is the measure of the flow of electric charge through a…
Correct answer: Rate of flow of charge- A. Power is proportional to voltage only
- B. Power is proportional to current only
- C. Power is neither proportional to voltage nor to the current
- D. Power is proportional to both voltage and current
Explanation: Power:The work done in moving the charges in a unit time is called the electric power.Electric Power= Work done in electric circuit/ time…
Correct answer: Power is proportional to both voltage and current- A. 6.4 A, 6.9 A
- B. 6.4 A, 9.6 A
- C. 4.6 A, 6.9 A
- D. 4.6 A, 9.6 A
Explanation: The current flows through a resistor R1=I1= I ( R2 ) / R1 + R2 = 16×(12/20) = 9.6 AThe current flows through the resistor R2=I2= I ( R1 )…
Correct answer: 6.4 A, 9.6 A764. A resistance of 40 Ohms is attached to a circuit having current of 300 Amperes. Find the voltage:
- A. 12,000 volts
- B. 15,000 volts
- C. 20,000 volts
- D. 300 volts
Explanation: Resistance=40 ohms Current=300 A Voltage=?By ohm's law; V=IR V=(300)(40) V=12000 VHence,A is the correct option.
Correct answer: 12,000 volts- A. Doubled
- B. Half
- C. Remains the same
- D. Increase three times
Explanation: Resistivity is the property of the material in the wire that depends on the chemical composition of the material but not on the amount of…
Correct answer: Remains the same- A. Temperature of the material is decreased
- B. Temperature of the material is increased
- C. Number of free electrons available becomes more
- D. None of the above options is correct
Explanation: a) Temperature of the material is decreased:Correct! The resistance of a material decreases when its temperature is decreased.
Correct answer: Temperature of the material is decreased- A. circuit is closed
- B. current is max
- C. circuit is open
- D. all of these
Explanation: Electromotive force (EMF) is equal to the terminal potential difference when no current flows and In the open circuit the current can not…
Correct answer: circuit is open- A. As long as possible
- B. As short as possible
- C. Neither too small neither too large
- D. Very thick
Explanation: A longer slide wire allows for finer resolution because it increases the overall resistance range available for measurement.
Correct answer: As long as possible769. An electric iron is 20V & 500W . The unit consumed by it (in kJ) in using it for 24 hours will be:
- A. 12
- B. 24
- C. 5
- D. 1100
Explanation: Power = energy/time500 = E/24E = 500 x 24 = 12,000 J
Correct answer: 12- A. H1=H2
- B. Hl < H2
- C. Hl>H2
- D. Hl > H2
Explanation: In series resistance, R(series) =R1 †R2 So, H1 =V² /R (series) In parallel 1/R (parallel)=1/R¹ † 1/R²So, H2 =V²/R(parallel)Here, the R…
Correct answer: Hl < H2- A. 12 Ω
- B. 11/12 Ω
- C. 12/11 Ω
- D. The data is insufficient
Explanation: As more and more resistors are added in parallel to a circuit, the equivalent resistance of the circuit decreases and the total current of…
Correct answer: 12/11 Ω- A. 1 x 10^-7
- B. 2.63 x 10^-8
- C. 19 X 10^-8
- D. 7.85 x 10^-8
Explanation: R=V/I = 2Ohm p=2 x 2.5 x 10^ -7 / 5= 1 x 10^-7 ohm.meter
Correct answer: 1 x 10^-7- A. Resistance will be doubled and specific resistance will be halved
- B. Resistance will be halved and the specific resistance will remain unchanged
- C. Resistance will be halved and the specific resistance will be doubled
- D. Resistance and specific resistance will both remain uncharged
Explanation: R= ρ L/A Ρ is a constant so it won't change. l/r^2= 2L/(2r)^2 2L/4r^2 ½ resistance and specific resistance will remain unchanged so B.
Correct answer: Resistance will be halved and the specific resistance will remain unchanged- A. 250 seconds
- B. 350 seconds
- C. 400 seconds
- D. 500 seconds
Explanation: Q = I x t so, t = Q / It = 5000 / 20 = 250 seconds
Correct answer: 250 seconds- A. Almost zero
- B. Almost infinite
- C. No prediction at all
- D. May increase or decrease
Explanation: At absolute zero i.e, 0K which is also the minimum temperature, the Resistance of the conductor becomes minimum but not exactly zero.
Correct answer: Almost zero776. In a conductor, if a 6-coulomb charge flows for 2 seconds. The value of electric current will be:
- A. 3 Amperes
- B. 3 Volts
- C. 2 Amperes
- D. 2 Volts
Explanation: Option A is correct since the value of 3 Amperes is correct according to the electric current formula I = Q/t.As 6 coulombs of charge flow…
Correct answer: 3 Amperes- A. | = VR
- B. P=IV
- C. V = IR
- D. Both Options B and C are correct
Explanation: Option C is correct since the statement of Ohm's law is obeyed by stating that V is directly proportional to me under constant temperature…
Correct answer: V = IR- A. Infinite
- B. Zero
- C. Minimum
- D. Maximum
Explanation: Option A is correct since, in a short circuit, there is no resistance to the flow of charges so, a large number of charges flow in a very…
Correct answer: Infinite- A. 0.016 per degree celsius
- B. 32 per degree celsius
- C. 0.018 per degree celsius
- D. 0.00106 per degree Celsius
Explanation: The temperature coefficient of resistivity (α) is given by the formula: α = (R2 - R1) / (R1 x (T2 - T1)) where R1 is the resistance at…
Correct answer: 0.016 per degree celsius- A. very low
- B. very high
- C. varying
- D. constant
Explanation: This is one of the conditions of Ohm's law that it is applicable only when the temperature of the conductor remains constant.
Correct answer: constant